How many WATTS per gal?

[Gomer4378]

I'm just wondering how many watts per gal you can have before it's considered too much.

Or is the more the better?

Is the watts per gal of a mh diff from a t5, as in 400w with each lights be the same ( besides the multiple t5s to acomplish the task).

Is that why people go with mh? To get a higher wattage with 1 bulb?

I'm just curious at this point and have been looking at mh for in the future of my tank.

Thanks

[Tank2379]

I would say anywhere from 4-6 watts per gallon. Depending on what you have in your system.

[mgamer20o0]

guess your asking how much is too much on a sw tank?

[Gomer4378]

Yes, sw reef tank.

[melosu58]

No people go with the MH`s and t5`s because of their higher intensity. WPG is a broad and general guidline. In today`s lighting intensity and par are terms used.

[Gomer4378]

there is 10k, 15k, 20k, 6500k.
how does a person know which one they want to get?

do you want a variety of them all?

when you say to keep the lighting down to 6-7 hours, does that mean all lights so the tank is dark or just the main mh or t5's then leave some other light like florescents or something on.

sorry for all the ?'s, I'm really trying to figure out the whole lighting thing.

[Ziggy953]

I have 4' 120g tank. Right now I have dual 175w MH bulbs with dual 110w VHOs and 2x54w T5s = 678W of light. I just picked up 2 250w MH ballast that will replace the 175s so I will be up to 828w of light.

My MHs are on for 8 hours per day, left on then right on left off then right off. My T5s and VHOs are on for 11 hours per day. Sunrise and sunset effect. I'm gonig to reduce the MH period when I put the 250s on to probably 6-7 hours. Not sure yet.

[Gomer4378]

Thanks Ziggy,
That puts the lighting in perspective for me.

Then the type of bulb used (10,15,20,ect.) is more of a personal preference?

[thincat]

What I believe is that the lower k value, the more yellow the light. The higher the k the more blue the light looks. The middle k values give you a very white look. That is why you supplement the mh with vho or t-5s so you can add actinic blue to the mix. If that is wrong someone correct me please...

[Ziggy953]

Thincat you are correct.

I use 10,000K bulbs on my reef and frag system so I can get good growth. I've used several others and didn't like the look. So what color temp you use is up to you and what you like your tank looking like.

[Innovator]

Originally Posted by Gomer4378

I'm just wondering how many watts per gal you can have before it's considered too much.

Or is the more the better?

As Melosu stated, the wpg rule is quite an old rule and can be used as a general guideline, but it has its faults. Par is of more importance. Is more better? Not necessarily and depending on the coral (including some fish) can inhibit growth.

Is the watts per gal of a mh diff from a t5, as in 400w with each lights be the same ( besides the multiple t5s to acomplish the task).

Is that why people go with mh? To get a higher wattage with 1 bulb?

A metal halide acts as a spotlight, it is a direct source of energy/illumination that allows better penetration whereas T5's, power compacts, and vho lighting spreads out across the entire length of the bulb. T5's run a bit cooler than halides, but the depth penetration is not as good. You also get far more bulb options with T5.

there is 10k, 15k, 20k, 6500k.
how does a person know which one they want to get?

do you want a variety of them all?

The K rating is just the aesthetic value. Each brand has different options in metal halide bulbs. Here is a decent link to get an idea between the differences in aesthetics: http://www.marinedepot.com/ps_Aquari...bs_information
You get far more bulb options with T5: http://www.reefgeek.com/lighting/T5_Fluorescent/Bulbs/

when you say to keep the lighting down to 6-7 hours, does that mean all lights so the tank is dark or just the main mh or t5's then leave some other light like florescents or something on.

Most halides are kept on about 8hrs give or take with actinics extending 10-12hrs. Corals do need their "down time" and especially from intense lighting. Moonlights can stay on all the time if you want.

[Gomer4378]

Thanks all,
I think I'm ready to jump into the whole lighting thing now without worry.

One last thing,
Some of the my fixtures that I have come across say hydroponics or growing light, are these the same thing?

[welsummer]

Watts per gallon is also dependant on the amount of live aquatic plants you have in your tank. If you have lots of plants, then you will need more light as the plants produce oxygen when they photosynthesis in the light and produce CO2 when they respire in the dark. Not providing enough light could cause your dissolved oxygen to drop and fish to die. If you have lots of plants, the more light and longer left on the better!